1. Field of the Invention
The present invention relates to an adhesion structure for adhesion of a box member to a plane, more particularly to an adhesion structure for adhesion of a terminal box to a solar cell module.
2. Related Background Art
There are conventionally known solar cell modules formed by sealing a solar cell element with a resin on a reinforcing plate such as a steel plate or a glass plate and covering them with a protective film. Output terminals of the solar cell module are of a screwing type, a lead wire type, or a socket type and in either case terminal boxes having waterproof structure are often provided for insulation.
The terminal boxes normally adhere to the back surface of the solar cell module with such an adhesive as a silicone sealant. When the terminal boxes simply adhered to the solar cell module, the adhesive flowed out from the edge of the terminal box during adhesion. When the terminal box adhered in this way suffered peeling force in a vertical direction to the solar cell module, there arose the problem that peeling occurred at the interface between the terminal box and the adhesive.
In general, as to an adhesive strength between the adhesive and the terminal box, it is known that a shear adhesion strength is greater than an adhesion strength in the peeling direction. Adhesion between the terminal box for the solar cell module and the adhesive should desirably be so strong as to endure before cohesive failure of the adhesive, without peeling at the interface between the adhesive and the terminal box.
For solving the above problem, the adhesive strength of the terminal box was conventionally increased by pushing the terminal box applied with the adhesive against the solar cell module and thereafter leveling the adhesive by finger or by spatula to attach the adhesive to the side surfaces of the terminal box, or applying an additional adhesive to the edge of the adhered portion between the terminal box and the solar cell module, or performing a similar procedure.
These procedures, however, take a lot of time and labor and have the problem that when the terminal box adhered suffers a peeling force in a vertical direction to the solar cell module, peeling occurs at the interface between the terminal box and the adhesive, except for the adhesive portions adhering to the side surfaces.
In the case where the terminal box is attached to the solar cell module, a lager adhesive strength is sometimes required in a limited space.